Testing apparatus and method for thin film transistor display array

Abstract

A testing circuit and method for thin film transistor display array, for testing the yield of a thin film transistor array is provided. The testing circuit includes an array tester, a test panel (DUT) and a sense amplifier array. The sense amplifier is composed of a plurality of trans-impedance amplifier units and a plurality of parasitic capacitance discharge circuit units. Every sense amplifier includes a trans-impedance amplifier, which is implemented by an operational amplifier, two switches and an operation capacitance. The trans-impedance amplifier is used to form an integrated circuit and the output is transmitted to a sampling / hold circuit via a switch. Also included is a parasitic capacitance discharge circuit that is used to form a discharge route for the charge of the parasitic capacitance.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a circuit testing method. In particular, the present invention relates to a testing method for pixel storage capacitance of a thin film transistor display circuit. A reliable and precise testing result of the yield can be obtained in conditions that parasitic capacitance is much larger than a pixel capacitance.[0003]2. Description of the Related Art[0004]The pixels of liquid crystal display (LCD) or organic liquid crystal display (OLED) become more and more, the area of large area display also become larger and larger, the parasitic capacitance Csp of the source line of the thin film transistor would be much more larger than the pixel storage capacitance Cs. The measuring signal is too small in yield testing of quality control step, so that the accuracy is not good enough.[0005]Generally, to measure the yield of the pixel capacitance, it is always to charge the pixel capacitance with a v...

AI Technical Summary

Benefits of technology

"The present invention provides a testing circuit and method for thin film transistor display array testing. The testing circuit includes an array tester, a device under test platform, and a sense amplifier array. The sensing circuit is designed to analyze and calculate the testing results. The testing method involves charging the pixel storage capacitors, discharging the operation capacitors of the sense amplifiers and discharge circuits, and testing the next pixel. The technical effects of the invention include improved accuracy and efficiency in testing thin film transistor display arrays."

Problems solved by technology

The measuring signal is too small in yield testing of quality control step, so that the accuracy is not good enough.

However, the parasitic capacitance is also charged simultaneously, and the signal is difficult to separate.

This prior art method needs a two stage measurement, must take a long time, the signal is also too weak, the reliability is not enough and the accuracy is also bad, may not meet the requirement of the industry.

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